4.
Log4J

When openjpa.Log is set to log4j, OpenJPA
will delegate to Log4J for logging. In a standalone application, Log4J logging
levels are controlled by a resource named log4j.properties
, which should be available as a top-level resource (either at the top level of
a jar file, or in the root of one of the CLASSPATH
directories). When deploying to a web or EJB application server, Log4J
configuration is often performed in a log4j.xml file
instead of a properties file. For further details on configuring Log4J, please
see the Log4J
Manual. We present an example log4j.properties file
below.